The peptide derivatives produced according to the present invention are suitable for the quantitative determination of certain proteolytic enzymes of class EC 3.4.4 and especially for thrombin (EC is the abbreviation for “Enzyme Committee” of the International Union of Biochemistry).
Methods for the synthesis of such related peptides have been described e.g. in U.S. Pat. No. 4,428,874 (1984), U.S. Pat. No. 4,070,245 (1978) and U.S. Pat. No. 4,629,695 (1986). These methods are based on solution phase synthesis using different amino acid derivatives.
However, the methods described in the art are not satisfactory with regard to the optical purity of the desired isomer and regarding the efforts needed for the purification of the respective peptides.
Accordingly, the object of the present invention therefore is to provide a more economic process for the manufacture of the peptide derivative of formula 1 in good yield and high optical purity.
The object has been achieved with the process of the present invention according to the claims herein.